When you realize you’re in “good days” the feeling is called bittersweet. Therefore one should make the most, as soon as you realize the time is bittersweet. This helps prevent regrets of “not doing enough” later. Like today, it’s not too late to make the most of your upcoming weekend.
Rule of thumb: it will always get worse in some way, so you will always remember the past fondly, also because you usually tend to forget the bad parts.
I remember I was sad a lot in my childhood, and why. I still look back on it fondly, likely because now I know how the things that made me sad get better/solved in the future, and because my childhood was free of a problem I currently struggle with now.
And on a much shallower note, the pop music that got played everywhere all the time was music I actively enjoyed.